// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/json/json_reader.h"

#include "base/json/json_parser.h"
#include "base/logging.h"
#include "base/values.h"

namespace base {

// Values 1000 and above are used by JSONFileValueSerializer::JsonFileError.
static_assert(JSONReader::JSON_PARSE_ERROR_COUNT < 1000,
    "JSONReader error out of bounds");

const char JSONReader::kInvalidEscape[] = "Invalid escape sequence.";
const char JSONReader::kSyntaxError[] = "Syntax error.";
const char JSONReader::kUnexpectedToken[] = "Unexpected token.";
const char JSONReader::kTrailingComma[] = "Trailing comma not allowed.";
const char JSONReader::kTooMuchNesting[] = "Too much nesting.";
const char JSONReader::kUnexpectedDataAfterRoot[] = "Unexpected data after root element.";
const char JSONReader::kUnsupportedEncoding[] = "Unsupported encoding. JSON must be UTF-8.";
const char JSONReader::kUnquotedDictionaryKey[] = "Dictionary keys must be quoted.";

JSONReader::JSONReader()
    : JSONReader(JSON_PARSE_RFC)
{
}

JSONReader::JSONReader(int options)
    : parser_(new internal::JSONParser(options))
{
}

JSONReader::~JSONReader()
{
}

// static
std::unique_ptr<Value> JSONReader::Read(StringPiece json)
{
    internal::JSONParser parser(JSON_PARSE_RFC);
    return parser.Parse(json);
}

// static
std::unique_ptr<Value> JSONReader::Read(StringPiece json, int options)
{
    internal::JSONParser parser(options);
    return parser.Parse(json);
}

// static
std::unique_ptr<Value> JSONReader::ReadAndReturnError(
    const StringPiece& json,
    int options,
    int* error_code_out,
    std::string* error_msg_out,
    int* error_line_out,
    int* error_column_out)
{
    internal::JSONParser parser(options);
    std::unique_ptr<Value> root(parser.Parse(json));
    if (!root) {
        if (error_code_out)
            *error_code_out = parser.error_code();
        if (error_msg_out)
            *error_msg_out = parser.GetErrorMessage();
        if (error_line_out)
            *error_line_out = parser.error_line();
        if (error_column_out)
            *error_column_out = parser.error_column();
    }

    return root;
}

// static
std::string JSONReader::ErrorCodeToString(JsonParseError error_code)
{
    switch (error_code) {
    case JSON_NO_ERROR:
        return std::string();
    case JSON_INVALID_ESCAPE:
        return kInvalidEscape;
    case JSON_SYNTAX_ERROR:
        return kSyntaxError;
    case JSON_UNEXPECTED_TOKEN:
        return kUnexpectedToken;
    case JSON_TRAILING_COMMA:
        return kTrailingComma;
    case JSON_TOO_MUCH_NESTING:
        return kTooMuchNesting;
    case JSON_UNEXPECTED_DATA_AFTER_ROOT:
        return kUnexpectedDataAfterRoot;
    case JSON_UNSUPPORTED_ENCODING:
        return kUnsupportedEncoding;
    case JSON_UNQUOTED_DICTIONARY_KEY:
        return kUnquotedDictionaryKey;
    default:
        NOTREACHED();
        return std::string();
    }
}

std::unique_ptr<Value> JSONReader::ReadToValue(StringPiece json)
{
    return parser_->Parse(json);
}

JSONReader::JsonParseError JSONReader::error_code() const
{
    return parser_->error_code();
}

std::string JSONReader::GetErrorMessage() const
{
    return parser_->GetErrorMessage();
}

} // namespace base
